Abrading apparatus



De 21, 1943- R. B. HU'YETT l-:TAL 2,337,048

- ABR'ADING APPARATUS Filed Sept. 3, 1941 2 Sheets-Sheet 1 aM/A Ummm A wDec. 21, 1943.

R. B. HUYETT ETAL ABRADING APPARATUS Filed Sept. 5, `1941 2 Sheets-Sheet2 (ju/wwwa C, Ilm a 4 a .n .L n/ .HU 3 @E Patented Dec. 2.1, 1943 angelsABRADING APPARATUS Robert B. Huyett and Charles M. Gossard,

Hagerstown, Md., assignors to Pangborn Corporation, Hagerstown, Md., acorporation of Maryland Application September 3, 1941, Serial No.409,420

12 Claims.

in part and underblasted in part. To overcome this defect, variousexpedients have been proposed, such as supporting the Workpieces upon aspindle and effecting their rotation While passing through the blaststream. This is an expensive arrangement in that conveyors of specialtypes as well as special driving means to effect rotation of theworkpieces must be provided and maintained. It has also been proposed tomove the blasting means as the article passes thereby. Again additionalmechanism is required with its attendant initial cost and maintenance.1n both arrangements, the maintenance cost is considerable because ofthe tendency of the abrasive used to get into the moving parts of themechanism and cause undue frictional wear.

In overcoming the aforesaid disadvantages of the prior art, it is anobject of ,this invention to provide ei'licient blast cleaning meanswherein a conveyor of relatively simple type can be employed incombination with substantially fixed blasting means, the necessity for,complicated mechanisms for eecting rotation of the workpieces ordisplacement of the yblastingY means being eliminated.

A further object of this invention is the provision of blastingapparatus including the combination of a relatively simple conveyor witha novel arrangement of blasting means whereby all surfaces of theworkpieces are substantially uniformly cleaned with a minimumexpenditure o blasting effort in a minimum of time.

Still a further object of this invention is' the provision of amulti-pass conveyor in combination with a novel arrangement of blastingmeans whereinthe total blasting effort is efciently utilized touniformly clean all surfaces of the workpieces under treatment, therebyavoiding wasteful overblasting and undesirable underblasting of thesurfaces.

Further objects of the invention will appear from the followingdescription and claims considered in connection with the` attacheddrawings, wherein Figure 1 is a plan of a preferred embodiment of theinvention, portions of the housing being removed to show the interior.

Fig. 2- is a side elevation of the apparatus of Fig. 1, a portion of theside wall being removed to illustrate the workpieces therein.

Fig. 3 is a section taken onl the line 3-3 of Fig. 1.

Fig. 4 is a side elevation of one of the work supports.

Fig. 5 is a diagrammatic illustration taken on line 3-3 of Fig. 1 andillustrating the manner in which the various blasts are eiiective on theworkpieces.

The embodiment herein described, Which is to be understood as onlyillustrative of one application of the present invention, comprises ahousing generally indicated at H which includes side walls Il and i2, aceiling I3, and a base M, the side walls and ceiling being connected andsupported in conventional manner as by angle irons or the like.

A conveyor l5 of the monorail type is provided to convey the workpiecesthrough the housing in two separate substantially vertically spacedpaths. Conveyor I5 includes a rail I6 entering housing H at the left endas viewed in Fig. i, making a complete turn at the right end at 2li andre-entering the housing and leaving at the left end. Rail I is securedto ceiling i3 of the housing and to a bracket I1 secured to the sidewall I2 in any suitable manner so that thevtwo rail sections in thehousing are at diferent elevations as shown in Figs. 3 and 5, and insubstantially vertical alignment.

A series of work supports I9 (Figs. 3 and 4) each comprising two yokedroller assemblies 2l,

with an arm 22 extending downwardly from each yoke, and a connectinglink 23, are provided to run on rail I5, each of roller assemblies 2lbeing secured to a, continuous chain 26 driven by suitable drive meansto move the work supports along rail I6.. A plurality of rods 25 of theshape shown in Figs. V3 and 5, and with hooks 26 thereon, are secured tolinks 23 by angle bracket and pin assemblies 25 to support workpiecessuch as crank shafts 27. As shown in Figs. 3 and 5, work supporting`rods 25 are shaped in such manner that workpieces 21 carried therebyare in Vertical alignment and spaced vertically from one another in thetwo paths of travel through the housing. By reason of the verticalalignment of the upper and lower sections of rail lll, any workpiecesthereon will be maintained in vertical alignment regardless of theirsize or shape.

It is to be understood that different types of work supports will beused for dierent types of workpieces, such as cylinder blocks, crankshafts, cylinder heads, or other articles, the present illustrationbeing particularly adapted for crank shafts of internal combustionengines. It is also to be noted that the conveyor mechanism providesonly for translation of the workpieces, and no rotation of theworkpieces during their travel through the housing is involved.

To prevent leakage of the flying abrasive. at the ends of the blastingzones, panels or baffles 2S are preferably provided, as shown-in Figs. 1and 3, each panel being provided with an opening through which the worksupports and the workpieces may pass.

To further prevent leakage of the flying abrasive from the ends ofhousing H, an entrance vestibule 3l and an exit vestibule 32 areprovided at each end of the housing, a plurality of curtains 33 offlexible material, such as rubber or fabric, being placed in each of thevestibules to provide a series of lock chambers through which theworkpieces must pass. Separate vestibules for entrance and exit of theworkpieces at each end of the housing are preferably provided to preventall curtains 33 of any one vestibule being maintained open by thepassage of two work supports therethrough simultaneously.

Side walls ll and l2 are preferably extended outwardly (Fig. l) toprovide blasting zones, or chambers, each chamber being defined by twooblique walls 34 and 35 and a well Sfjsubstantially parallel to the sidewalls. One or more abrasive throwing or blasting means, preferablyemploying centrifugal wheels 31 of the type shown in Keefer Patent No.2,246,522, issued on June 24, 1941, are mounted on walls 3B and 35 asshown at A, B, C, and D. In addition to the throwing wheel, each of saidunits includes a housing 38, a shaft 39 supported on the side wall, andsuitable drive means for the shaft, such as an electric motor Abrasivemay be fed to the wheels 31 through feed spouts l2 which, in turn, arefed from a suitable overhead hopper (not shown).

It is characteristic of such centrifugal wheels that they projectabrasive in a rectangular pattern with the abrasive being most denselinthe so-called head stream adjacent one end of the pattern, and taperingorf in density to the socalled tail stream at the opposite ,end of thepattern. Such wheels can be arranged androtated so that they dischargeabrasive from a point on their upper periphery in which case they arecalled over-shot wheels, or discharge abrasive from their lowerperiphery, in which, case they are called undershot wheels.

In the present invention, each ofV the blast wheels is positioned sothat its blast is directed simultaneously onto the articles` supportedby each pass of the conveyor. In addition, some of the wheels yare ofthe over-shot type, and some` of the under-shot type (dependent uponthesize, and shape of the workpieces) and are positioned to direct theirblasts at predetermined angles to the direction of travel and theworkpieces so that as a result of the total treatment, the articles aresubstantially uniformly cleaned on all surfaces, this being accomplishedwithout the necessity of providingwmeans torotate, reciproside surfacesopposite to those cate, or otherwise move the articles except in simpletranslation, the blast means being maintained stationary.

In operation, the workpieces are loaded upon work supports 25 andtranslated through the housing by chain 2d at a substantially steadyspeed. After its initial pass through the housing, each workpiece isturned end for end in loop 29 at the right end of the housing andreturned for its second pass.

For purposes of economy to avoid extra handling, it is desirable to makerail It a part of the regular conveyor system of the` plant in whichcase it is not necessary to load and unload the workpieces on a specialblasting conveyor.

In the operation of the embodiment herein described, the workpieces areconveyed through housing H in the rst pass of the conveyor, which ispreferably on the portion of rail I6 supported at the higher level.Referring to Figure 5 which is a section similar to Fig. 3 and in whichthe wheels have been shown diagrammatically with the vertical outlinesof their blast patterns, in passing wheel A which is at a high level andpreferably of the undershot type, the right sides and portions of theupper surfaces of the workpieces W1 and W2 are cleaned by the tailportion of the blast stream, the outer limit of which is shown at At, aswell as the surfaces facing opposite the direction of travel of theworkpieces, the latter being caused by the inclination of the blast fromA at an angle toward the direction of travel of the workpieces W 1 andW2. At the saine time, the head stream from wheel A, bounded by the lineAh is effective upon the right side, and the upper and forwardly facingsurfaces of workpieces W3 and W4 which are traveling in the oppositedirection on the lower level pass of the conveyor suspended from bracketIl.

As workpeces W1 and W2 continue their travel, they encounter the blastfrom wheel B which is positioned at a lower level than wheel A andpreferably of the overshot type. The

' headportion of the blast from wheel B, dened at its outer boundary bythe line Bh is effective'on the right side, the under surfaces and the`forwardly facing surfaces of workpieces W1 and W2. At the same time, thetail portion of the B wheel blast, dened at its outer boundary by theline Bt is effective upon the right, portions of the upper, and therearwardly facing surfaces of workpieces W3 and W4 that aresimultaneously passing wheel B. It is to be understood that the latterworkpieces are not the same workpieces that were just referred toconnection with wheel A as the conveyor has now moved forward.

In continuing their travel, workplaces W1 and W2 next encounter theblast from wheel C, which is awheel somewhat similar to wheel A, mountedat a high level and of the under-Shottype, except that it is positionedatA the opposite side of the housing. The blast pattern produced bywheelC is similar to that of the pattern from Wheel A. except that theopposite side surface offthe Workpieces are blasted. The outer boundaryof the tail stream for Wheel C is indicated at Ct'and the outer boundaryof the head stream at Ch.

As the workpieces continue their travel, they enter the blast from wheelDwhich resembles that of wheel B in thatit is at a low level and o-f theover-shot type.

In passing through the blast from wheel D, the blasted by wheel B areblasted in addition to portions of lower surfaces, and the forwardlyfacing surfaces of Work- Ipieces W1 and W2. The outer boundary of thetail stream of wheel D is indicated at Dt and the outer boundary of thehead stream is indicated at Dh.

It is to be understood that in the above described operation of units Cand D, workpieces W 3 and W 4 on the lower level run of the conveyor arebeing simultaneously treated by the blasts from those units.

Where workpieces such as relatively simple blocks are to be cleaned, itis possible to use only one set of blasting units, that is either wheels.A and B, or wheels C and D, the workpieces being reversed by the loopin the conveyor rail so that a different side is exposed to the blastsduring the different passes through the housing. However, withworkpieces of complicated shape and with numerous recesses therein, suchas crank shaftsand cylinder blocks, the arrangement disclosed herein ispreferred.

By the use of the conveyors at diierent elevations, the arrangement ofover-shot and undershot blast units, and the blast patterns projected atpredetermined angles relative to the travel of the workpieces, it hasbeen found possible to clean all surfaces of the individual workpiecesuniforrnly with substantially on underblasting or overblasting. Becauseof the arrangement of the path of the workpieces in planes spaced fromone another, the entire effect of each blast is utilized at all timeswith no interference of the blast on one workpiece by the presence ofanother workpiece in the blast.

While the blast chambers defined by walls 3d, 35, and 36 have been shownas spaced longitudinally of the housing, it is to be understood thatthey may be arranged opposite one another with the opposing wheels instaggered relation or in other positions, the only controlling factorbeing the necessity of avoiding direct conict of opposing blasts.

In the illustrated embodiment of the invention, the selection of thevarious wheels as of the under-shot or the over-shot type has beengoverned by the type of workpiece being cleaned therein, such as, crankshafts. If other types of workpieces are being cleaned, such as cylinderblocks,

such wheels as wheel A of the illustrated embodiment are preferably ofthe over-shot type and such Wheels as wheel B are preferably of theunder-shot type.

It is to be understood that the invention may be embodied in specicforms other than that illustrated without departing from the principleor essential characteristics thereof. The embodiments shown aretherefore to be considered as illustrative and not restrictive, thescope of the invention being defined by the appended claims rather thanthe foregoing description and drawings. All modifications and changeswhich come within the meaning and range of equivalency of the claims aretherefore intended to be included therein.

We claim:

l. Blasting means comprising a housing, means to transport workpieces tobe blasted through said housing in one path and return said workpiecesthrough said housing in a second path spaced from said rst path in apredetermined plane, and a plurality of centrifugal blasting wheels insaid housing positioned to blast said workpieces as they are transportedalong said lpaths, said wheels being spaced along one side of said pathsand spaced apart in a plane substantially parallel to the plane of thepaths of said workpieoes, one of said wheels being positioned to directits blast at an acute angle relative to the direction of travel of saidworkpieces and another of said wheels being positioned to direct itsblast at an obtuse angle relative to the direction of travel of saidworkpieces.

2. Blasting means comprising a housing, means to transport articles tobe blasted through said housing in one path and return said workpiecesthrough said housing in a second path spaced in a predetermined planefrom said rst path, and a plurality of centrifugal blasting wheels insaid housing positioned on opposite sides of the plane of said paths andspaced from one another in a plane substantially parallel to the planeof said paths, at least one of said wheels being arranged to direct itsblast at an acute angle to the direction of travel of the workpiecesalong one of said paths and another wheel arranged to direct its blastat an obtuse angle to the direction of travel of the workpieces alongsaid same path, each of said blasting wheels being arranged to directits blast simultaneously on workpieces in both paths.

3. Blasting means comprising a housing, means to transport workpieces tobe blasted through said housing in one path, turn said worlzpieces endfor end, and return them through said housing in a second path spaced ina predetermined plane from said rst path, and a plurality of centrifugalblasting wheels in said housing positioned on opposite sides of theplane of said paths and spaced from one another in a plane substantiallyparallel to the plane of said paths, at least one of said wheels beingarranged to direct its blast at an acute angle to the direction oftravel of the workpieces along one of said paths and another wheelarranged to direct its blast at an obtuse angle to the direction oftravel of said workpieces along said same path, each of said blastingwheels being arranged to direct its blast simultaneously on workpiecesin both paths.

4. The combination claimed in claim 3 wherein said wheels are arrangedin pairs, one wheel oi each pair being of the overshot type and thecther wheel being of the undershot type.

5. Blasting means comprising a housing, means to transport workpieces tobe blasted in a horizontal path through said housing, means to turn saidworkpieces end for end, and return them through said housing in a secondhorizontal path vertically spaced from said first path, and a pluralityof centrifugal blasting wheels in said housing positioned on oppositesides of said paths and at different levels; the lower wheels being ofthe overshot type and the upper wheels of the undershot type, at leastone of said wheels being arranged to direct its blast at an acute angleto the direction of travel of the workpieces along one of said paths andanother wheel arranged to direct its blast at an obtuse angle to thedirection of travel of said workpieces along said same path, each ofsaid blasting wheels being arranged to direct its blast simultaneouslyon workpieces in both paths.

6. Blasting means comprising a housing, means to transport workpieces tobe blasted through said housing in one path and return them through saidhousing in a second path spaced from said rst path in a predeterminedplane, and a plurality of blasting means for blasting said workpieces,each of said blasting means being of a type to project a blasting mediumin an elongated pattern, varying in intensity from one end of saidpattern to the opposite end, at least one of said wheels being arrangedto project its blast of greatest intensity upon the workpieces in saidrst path while simultaneously projecting its blast of least intensityupon the workpieces in said second path, and another oi said wheelsbeing arranged to project its blast of greatest intensity upon theworkpieces in said second path while simultaneously projecting its blastof least intensity upon the workpieces in said first path.

'7. The combination claimed in claim 6 wherein one of said wheels ispositioned to direct its blast at an acute angle relative to the planeof said paths and another of said wheels is positioned to direct itsblast at an angle of about 90 from the angle of said rst means wherebythe workpieces transported along said paths will encounter blasts angledtoward their direction of travel and opposite to their direction oftravel.

8. In apparatus for abrading articles, a housing, a rail sectionextending through the housing, a rail loo-p at one end of said railsection, another rail section extending from said loop through thehousing below the first rail section, means movable on said railsections and said rail loop for supporting articles to be abradedwhereby the articles in moving through the housing on said means aresupported in one path and turned end for end by said rail loop andsupported entirely below the rst path during return movement through thehousing, and means at one side of said housing for projecting particlesat abrading velocities in a pattern of such vertical dimensions that theprojected particles engage the articles during both paths of movementthrough the housing.

9. In apparatus for abrading articles, an elongated housing, a railsection having a substantially straight portion extending longitudinallyof the housing, a rail loop at one end of said straight portion, anothersubstantially straight rail section extending from said looplongitudinally of the housing and positioned substantially verticallybelow the rst rail section, means movable on said rail sections and saidrail loop for supporting articles whereby the articles in movinglengthwise of the housing are supported by said means on one straightrail section and turned end for end by said rail loop and supported bysaid means on the other rail section during return movement in thehousing, and blasting means at one side of said housing for projectingparticles into engagement with articles supported by said means on bothstraight rail sections.

l0. In apparatus for abrading articles, a housing, a substantiallystraight rail section extending through said housing, a rail loop at oneend of said rail section, a second substantially straight rail sectionextending from said loop through the housing and spaced below the firsttrack section at a distance greater than the vertical heieht of anarticle to be abraded, article supports movable on said rail sectionsand said loop each support including a downwardly depending rod of afixed length arranged laterally of the rail sections and a hook forsupporting an article to be abraded vertically below both rail sections,and blasting means on said housing positioned to blast the articles asthey are moved through the housing on said hooks.

1l. In apparatus for abrading articles, a housing, a rail sectionextending through the housing, another rail section extending throughthe housing below the rst rail section and in a vertical plane definedby the first rail section, a rail loop connecting said rail sections,means movable on said rail sections and said rail loop for supportingarticles to be abraded whereby the articles in moving through thehousing on said means are supported in one path and turned end for endby said rail loop and supported in the vertical plane of the iirst pathduring return movement through the housing, and means at both sides ofsaid housing for hurling particles generally transversely of the housingin outwardly converging patterns of such vertical dimensions that thehurled particles engage the articles in both paths of movement throughthe housing whereby the angle at which the particles strike the articlesin one path diers from the angle at which the particles strike thearticles in the other path.

12. Apparatus for abraclinfI individual articles comprising, a housing,a rail section within said housing, a second rail section within saidhousn ing spaced below and in substantial vertical alignment with theiirst rail section, means movable on said rail sections for supportingindividual articles to be abraded, means for transferring said movablemeans from one rail section to the other rail section whereby individualarticles in moving within the housing are supported by said movablemeans on one rail section and by said transfer means and thereaftersupported on the other rail section, blasting means projecting particlesinto the housing and into engagement with the articles supported by saidmeans moving on both rail sections, and blasting means projectingparticles into the housing from a substantially opposite direction andinto engagement with the articles supported by said means moving on bothrail sections.

ROBERT B. HUYET'I. CHARLES M. GOSSARD.

V CERTIFICATE CE CORRECTION. Patent No. 2,557,0LI8. December 21, 191g.

ROBERT B. HUYETT, ET AL.

'is hereby certified that error appears in the printed specification ofthe above numbered patent requiring Correction as follows: Page 2, firstcolumn, line 57, for "well" read --wa11; page 5, first column, line 29,for "on" read -no; and that the said Letters Petent should be read withthis Co rrecti on therein that the same may conform to the record of thecase in the Patent Office.

signed and sealed this 18th Cay ef April, A. D. 19h14.

Leslie Frazer (Seal) Acting` Commissioner of Patents.

